It suggests that an optimum temperature of 19C is sufficient to provide the right balance.

Lead research Dr Wouter can Marken Lichtenbelt, from Maastricht University Medical centre, told the BBC: “19C is enough – and not for the whole day. Energy increases were in the order of 6% in mild cold, and in the long terms that could really make a difference.

“It could be a substantial influence and help in combinations with food changes and exercise.”

At least among young and middle-aged people, non-shivering heat production in response to feeling cold can account for up to 30% of the body’s energy budget, say the scientist. That means lower temperatures can significantly increase the number of calories burned up instead of being stored as fat.

One research group in Japan had shown a decrease in body fat after volunteers spent two hours a day at 17C for six weeks, said the scientist.

However, some believe that as we get cold we compensate with comforting foods which in turn lead to weight gain. Dr Michael Daly, who investigated the issue at the University of Stirling, told the BBC News: “If you didn’t compensate you would lose weight, but that’s not really how it happens. You will want a chocolate bar.

“Also, studies suggest that in cold indoor temperatures you are more likely to get a stroke and there is a [overall] winter mortality effect.”

His research on 100,000 homes in England suggested people in houses heated above 23C tended to be slightly thinner, because at this point the body needed to lose heat – and sweating used up energy.